The benefit: This exercise works your entire abdominal muscle complex while keeping your lower back in its naturally arched position. So it minimizes stress on your spine while increasing the endurance of the muscles, which helps prevent lower-back pain.

How to do it: Lie on your back on the floor with your right leg straight and flat on the floor. Your left knee should be bent and your left foot flat. Place your hands palms down on the floor underneath the natural arch in your lower back [A]. Slowly raise your head and shoulders off the floor without bending your lower back or spine, and hold this position for 7 to 8 seconds, breathing deeply the entire time [B]. That’s 1 rep. Do 4 to 5 reps, then switch legs and repeat. To make it even harder, raise your elbows off the floor as you curl up.

LATS Band-Assisted Chinup

The benefit: This exercise allows you to do full chinups, even if you’ve never managed a single one. Plus, it more accurately mimics the movement than lat pulldowns or the assisted chinup machine. All you need is a chinup bar and a large rubber band called a SuperBand.

How to do it: Loop one end of a SuperBand around a chinup bar and then pull it through the through the other end of the band, cinching it tightly to the bar. (The thicker the band you buy, the more assistance it will provide.) Grab the bar with a shoulder-width, underhand grip, and place your knees in the loop of the band. Hang at arm’s length [A]. Perform a chinup by pulling the top of your chest to the bar [B]. Pause, then slowly lower your body back to the starting position.

UPPER BACK Swiss-Ball L Raise

The benefit: This exercise targets your upper back. By working these key muscles, you’ll improve your posture, shape the back of your shoulders, and look great in a backless dress.

How to do it: Lie facedown on top of a Swiss ball so that your back is flat and your chest is off the ball. Let your arms hang straight down from your shoulders, your palms facing behind you [A]. Keeping your elbows flared out, lift your upper arms as high as you can by bending your elbows and squeezing your shoulder blades together. Your upper arms should be perpendicular to your torso [B]. Without changing your elbow position, rotate your forearms up and back as far as you can [C]. Pause, then reverse the movement. If you can do more than 12 repetitions, use dumbbells.

FOREARMS Plate Pinch Curl

The benefit: Strengthens the muscles of your forearms, hands, fingers, and thumbs, while also shaping your biceps. Bonus: Makes you better at opening jars, too.

How to do it: Grab a pair of light weight plates in your right hand. Hold the two plates together with your fingers and thumb by pinching the smooth side of the plates. Let the plates hang at arm’s length next to your side [A]. Without moving your upper arm, bend your elbow and curl the weights as close to your shoulder as you can [B]. Slowly lower the weights back to the starting position and repeat.

FOREARMS Plate Pinch Curl

The benefit: Strengthens the muscles of your forearms, hands, fingers, and thumbs, while also shaping your biceps. Bonus: Makes you better at opening jars, too.

How to do it: Grab a pair of light weight plates in your right hand. Hold the two plates together with your fingers and thumb by pinching the smooth side of the plates. Let the plates hang at arm’s length next to your side [A]. Without moving your upper arm, bend your elbow and curl the weights as close to your shoulder as you can [B]. Slowly lower the weights back to the starting position and repeat.

BICEPS Split Stance Dumbbell Curl

The benefit: Placing one foot in front of you on a bench forces your hip and core muscles to work harder in order to keep your body stable. That way, you engage more muscles and burn more calories than you would if you did the exercise in a regular standing position.

How to do it: Grab a pair of dumbbells and place one foot in front of you on a bench or step that’s just higher than knee level. Let the dumbbells hang at arm’s length next to your sides, your palms facing forward [B]. Without moving your upper arms, bend your elbows and curl the dumbbells as close to your shoulders as you can [B]. Pause, then slowly lower the weights back to the starting position. Each set, switch the foot that you place on the bench.

TRICEPS Swiss-Ball Lying Triceps Extension

The benefit: Lying on a Swiss ball forces your core to work harder to keep you stable. So you work your abs as you shape the backs of your arms.

How to do it: Grab a pair of dumbbells and lie on your back on a Swiss ball so that your middle and upper back are firmly on the ball. Raise your hips so that your body forms a straight line from your knees to your shoulders. Hold the dumbbells over your forehead, with your arms straight and your palms facing each other [A]. Without moving your upper arms, bend your elbows to lower the dumbbells until your forearms are beyond parallel to the floor [B]. Pause, then lift the weights back to the start by straightening your arms.

SHOULDERS Scaption and Shrug

The benefit: When you raise the dumbbells to start this exercise, you target the front of your shoulders as well as your rotator cuff. Then comes the shrug. This part of the move helps better balance the muscles that rotate your shoulder blades. The end result: Great-looking shoulders and better posture.

How to do it: Stand holding a pair of dumbbells with your feet shoulder-width apart. Let the dumbbells hang at arm’s length next to your sides, your palms facing each other [A]. Without changing the bend in your elbows, raise your arms until they’re parallel to the floor, keeping them at a 30-degree angle to your body (so that they form a “Y”) [B]. At the top of the movement, shrug your shoulders upward [C]. Pause, then reverse the movement to return to the start, and repeat.

CHEST Single-Arm Dumbbell Bench Press

The benefit: This exercise works your glutes and abs as hard as it works your chest and triceps. So you’ll tighten your hips and core as you tone your upper body.

How to do it: Grab a dumbbell in your left hand and lie on your back on a flat bench, holding the dumbbell over your chest with your arm straight. Your palm should be facing out, but turned slightly inward. Place your right hand on your abs [B]. Lower the dumbbell to the side of your chest. Pause, then press the weight back to the start. Want an even greater challenge? Slide over so that only your right butt cheek and right shoulder blade are on the bench. (Don’t let your hips sag; you’ll have to place your left foot wider to maintain your balance.) Do all your repetitions, then repeat on your right side.

CALVES Single-Leg Donkey Calf Raise

The benefit: This simple exercise helps shape your calves in the comfort of your living room.

How to do it: Place the ball of one foot on a step, block, or 25-pound weight plate. Cross your other foot behind your ankle. Grasp a sturdy object for support. Then keeping your back naturally arched, bend at your hips and lower your torso until your upper body is almost parallel to the floor [A]. Lift your heel as high as you can [B]. Pause, lower your heel, and repeat. Complete as many reps as you can–or for a duration of 60 seconds–then switch legs.

HAMSTRINGS Single-Leg Dumbbell Straight-Leg Deadlift

The benefit: Besides targeting your hamstrings, this exercise works your glutes and core. It also helps eliminate muscle imbalances between your legs, reducing your risk of injury. And as a bonus, it can even improve the flexibility of your hamstrings.

How to do it: Grab a pair of dumbbells with an overhand grip, and hold them at arm’s length in front your thighs. Stand with your feet shoulder-width apart and knees slightly bent. Now raise one leg off the floor [A]. Without changing the bend in your knee, bend at your hips (keep your lower back arched), and lower your torso until it’s almost parallel to the floor [B]. Pause, then squeeze your glutes, thrust your hips forward, and raise your torso back to the start. Do all your reps, then repeat with your other leg.

ABS Mountain Climber with Hands on Swiss Ball

The benefit: It’s one of the simplest yet most effective ways to tighten your tummy. In fact, you’ll barely have to move a muscle.

How to do it: Assume a pushup position with your arms completely straight, but place your hands on a Swiss ball instead of the floor. Your body should form a straight line from your head to your ankles. Tighten your core and hold it that way for the duration of the exercise [A]. Lift one foot off the floor and slowly raise your knee as close to your chest as you can without changing your lower-back posture. Then repeat with your other leg. Alternate back and forth for 30 seconds. If that’s too hard, place your hands on the floor or a bench, instead of a Swiss ball.